title: Crystallization and preliminary X-ray analysis of the TetR-like efflux pump regulator SimR.
abstract: Crystals of SimR were grown by vapour diffusion. The protein crystallized with trigonal symmetry and X-ray data were recorded to a resolution of 2.3 Å from a single crystal at the synchrotron. SimR belongs to the TetR family of bacterial transcriptional regulators. In the absence of the antibiotic simocyclinone, SimR represses the transcription of a divergently transcribed gene encoding the simocyclinone efflux pump SimX in Streptomyces antibioticus by binding to operators in the simR-simX intergenic region. Simocyclinone binding causes SimR to dissociate from its operators, leading to expression of the SimX efflux pump. Thus, SimR represents an intimate link between the biosynthesis of simocyclinone and its export, which may also provide the mechanism of self-resistance to the antibiotic in the producer strain.
authors.affiliation: Department of Molecular Microbiology, John Innes Centre, Norwich NR4 7UH, England.
authors.forename: Tung B K
authors.initials: TB
authors.lastname: Le
authors.forename: Clare E M
authors.initials: CE
authors.lastname: Stevenson
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Buttner
authors.forename: David M
authors.initials: DM
authors.lastname: Lawson
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D018360:Crystallography, X-Ray; D008969:Molecular Sequence Data; D012097:Repressor Proteins / Q000737:chemistry* / Q000235:genetics; D013303:Streptomyces antibioticus / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D012097:Repressor Proteins